Which GLP-1 drug is best for weight loss?
The most effective GLP-1 drug for weight loss currently (as of mid-2025) is tirzepatide, marketed under the names Zepbound (for weight loss) and Mounjaro (for diabetes). Clinical trials and recent meta-analyses consistently show tirzepatide delivers the most substantial weight reduction among GLP-1 medications, with average losses of up to 22.5% of body weight, outperforming semaglutide (Wegovy and Ozempic), which averages up to 15–16% weight loss.
GLP-1 receptor agonists have emerged as powerful tools for weight loss, with several options now available on the market. These medications work by slowing digestion and decreasing appetite, which leads to less calories consumed. When choosing the best GLP-1 drug for weight loss, some things to consider include effectiveness, dosage formulation, frequency of administration, cost, and side effects.
Current FDA-approved GLP-1 drugs available on the market include:
- Byetta, Bydureon (exenatide)
- Trulicity (dulaglutide),
- Victoza, Saxenda, Xultophy (liraglutide)
- Ozempic, Rybelsus, Wegovy (semaglutide)
- Mounjaro, Zepbound (tirzepatide)
While all GLP-1 drugs can cause weight loss as a side effect, only Wegovy, Saxenda, and Zepbound are FDA approved for this indication.
Who can use GLP-1 drugs for weight loss?
Healthcare providers may prescribe any of the GLP-1 drugs off-label for weight loss, but three GLP-1 drugs are approved by the FDA for weight management.
- Saxenda can be used in adults with a body mass index (BMI) of 30 kg/m2 or greater, or 27 kg/m2 or greater with at least one weight-related health condition. It is also approved for children 12 years and older with a body weight above 60 kg and a BMI corresponding to 30 kg/m2 for adults.
- Wegovy can be used in adults and children 12 years and older with obesity, and adults with overweight and one weight-related health condition.
- Zepbound can be used in adults with obesity or adults with overweight and one weight-related health condition.
Which GLP-1 Drug is Most Effective for Weight Loss?
As of mid-2025, the most effective GLP-1 drug for weight loss is tirzepatide (Mounjaro, Zepbound). Among the GLP-1 drugs currently available, tirzepatide and semaglutide both stand out as the most effective for weight management.
- A 2024 systematic review and meta-analysis that included 53 studies lasting between 12 and 78 weeks and 21,349 patients found that compared with placebo, tirzepatide worked the best for weight loss. This was followed by semaglutide, liraglutide, dulaglutide, and then exenatide. On average, patients taking tirzepatide lost about 8.5 kg (19 lbs). Those taking semaglutide lost about 3 kg (6.6 lbs).
- A 2025 head-to-head trial studying tirzepatide vs. semaglutide for obesity showed tirzepatide produced significantly greater reductions in body weight and waist circumference over 72 weeks compared to semaglutide, with both drugs having mostly mild-to-moderate gastrointestinal side effects during dose escalation.
How are GLP-1 Drugs Given?
GLP-1 drugs come in two main dosage forms: oral pills and subcutaneous (under the skin) injections. Those FDA approved for weight loss only come in the injection form.
- Bydureon comes as a subcutaneous injection that is given once a week.
- Byetta comes as a subcutaneous injection that is given twice a day.
- Mounjaro comes as a subcutaneous injection that is given once a week.
- Ozempic comes as a subcutaneous injection that is given once a week.
- Rybelsus comes as oral tablets that are taken by mouth once a day.
- Saxenda comes as a subcutaneous injection that is given once a day.
- Trulicity comes as a subcutaneous injection that is given once a week.
- Victoza comes as a subcutaneous injection that is given once a day.
- Wegovy comes as a subcutaneous injection that is given once a week.
- Zepbound comes as a subcutaneous injection that is given once a week.
Here is a table to summarize how GLP-1 medications come and how they are given:
| Drug | Form | Frequency |
|---|---|---|
| Bydureon | Subcutaneous injection | Once a week |
| Byetta | Subcutaneous injection | Twice a day |
| Mounjaro | Subcutaneous injection | Once a week |
| Ozempic | Subcutaneous injection | Once a week |
| Rybelsus | Oral tablet | Once a day |
| Saxenda | Subcutaneous injection | Once a day |
| Trulicity | Subcutaneous injection | Once a week |
| Victoza | Subcutaneous injection | Once a day |
| Wegovy | Subcutaneous injection | Once a week |
| Zepbound | Subcutaneous injection | Once a week |
Related questions
- Mounjaro vs Ozempic: Which is right for you?
- Zepbound vs Mounjaro: Comparison Guide for Weight Loss and Diabetes Treatment
- Why am I not losing weight on Mounjaro?
Which GLP-1 Drug Causes More Side Effects?
GLP-1 drugs share many common side effects. Most side effects are stomach-related, and include nausea, vomiting, diarrhea, and stomach pain. These side effects are more likely to occur at the start of treatment or after a dose increase.
In a 2024 systematic review and meta-analysis, researchers found that some GLP-1 drugs were more likely to cause diarrhea than others. The GLP-1 drugs that caused the most diarrhea were tirzepatide and semaglutide. Dulaglutide, liraglutide, and exenatide caused less diarrhea than tirzepatide and semaglutide. Compared to placebo, all of the GLP-1 drugs caused more nausea and vomiting.
What is the Cost of GLP-1 Drugs?
The cost of GLP-1 drugs can depend on insurance coverage and manufacturer assistance programs. Below is a list of cash prices for a one-month supply of GLP-1 drugs:
- Bydureon 2 mg: $510.95
- Byetta 10 mcg/0.04 mL: $896.60
- Mounjaro 5 mg/0.5 mL: $1,136.53
- Ozempic 2 mg/3 mL (0.25 mg or 0.5 mg dose): $1,050.73
- Rybelsus 7 mg: $1,050.73
- Saxenda 18 mg/3 mL: $1,417.62
- Trulicity 1.5 mg/0.5 mL: $1,039.88
- Victoza 18 mg/3 mL: $576.67 (a generic version is also available for $442.97)
- Wegovy 1.7 mg/0.75 mL: $1,417.62
- Zepbound 10 mg/0.5 mL: $1,143.42
These prices are based on using the Drugs.com discount card. The cash price can vary based upon your insurance and what pharmacy you go to.
Real-World Effectiveness: How Much Weight Can Patients Really Lose?
Recent studies show a clear gap between clinical trial results and real-world outcomes for GLP-1 agonists like semaglutide (Wegovy, Ozempic) and tirzepatide (Zepbound, Mounjaro). Despite headline-grabbing clinical results (up to 22% weight loss in trials), average weight reduction in routine care is typically 2–8% after a year, with only about one third of patients achieving greater than 5% loss. High discontinuation rates and lower real-world adherence dilute the results observed in pharmaceutical-sponsored studies. Even with these more modest real-world results, smaller amounts of weight loss can still yield meaningful cardiovascular and metabolic benefits.
GLP-1s Aren’t All the Same: Individualizing the “Best” Drug
Some GLP-1 drugs might be recommend over others depending on patient factors like other health conditions and preferences. For example:
- Tirzepatide (Zepbound) shows the greatest mean weight loss and is also approved for obstructive sleep apnea, but semaglutide (Wegovy) is preferred for those with cardiovascular or kidney complications or metabolic-associated steatohepatitis (MASH) due to broader FDA approvals.
- Daily injections (e.g., liraglutide/Saxenda) might suit highly motivated patients who want rapid titration, but most prefer weekly options.
- Oral GLP-1s (Rybelsus) are less effective, but could suit patients with aversion to needles.
Myth-Busting: GLP-1 “Supplements,” Drops, and Over-the-Counter Claims
FDA and medical experts warn that over-the-counter “GLP-1 boosters,” pills, or drops are not true medications. Supplements like “Lemme GLP-1 Daily” lack any regulated clinical data, do not boost natural GLP-1 at meaningful levels, and may even carry health risks when combined with prescription medications. The FDA routinely issues warnings or seizes products making unauthorized GLP-1 claims. Patients should avoid these in favor of physician-prescribed, FDA-approved therapies.
This is not all the information you need to know about GLP-1 drugs for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.
References
- Alali, S., Al-Otaibi, W., Ashodian, K., Achour, N., Almulla, A., & Mutlaq, H. (2025). A comparison of Glucagon-like peptide-1 receptor agonists on weight change, side effects, and quality of life in Kuwait. Frontiers in nutrition, 12, 1590379. https://doi.org/10.3389/fnut.2025.1590379
- Aronne, L. J., Horn, D. B., le Roux, C. W., Ho, W., Falcon, B. L., Gomez Valderas, E., Das, S., Lee, C. J., Glass, L. C., Senyucel, C., Dunn, J. P., & SURMOUNT-5 Trial Investigators (2025). Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. The New England journal of medicine, 393(1), 26–36. https://doi.org/10.1056/NEJMoa2416394
- Collins, L., et. al. 2024. Glucagon-Like Peptide-1 Receptor Agonists. In: StatPearls [Internet]. Accessed 02/10/2025 at https://www.ncbi.nlm.nih.gov/books/NBK551568/
- Gasoyan, H., Butsch, W. S., Schulte, R., Casacchia, N. J., Le, P., Boyer, C. B., Griebeler, M. L., Burguera, B., & Rothberg, M. B. (2025). Changes in weight and glycemic control following obesity treatment with semaglutide or tirzepatide by discontinuation status. Obesity (Silver Spring, Md.), 10.1002/oby.24331. Advance online publication. https://doi.org/10.1002/oby.24331
- Saxenda [package insert]. Updated November 2024. Novo Nordisk. Accessed 02/19/2025 at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3946d389-0926-4f77-a708-0acb8153b143
- U.S. Food and Drug Administration. (n.d.). FDA's concerns with unapproved GLP-1 drugs used for weight loss. Retrieved July 30, 2025, from https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/fdas-concerns-unapproved-glp-1-drugs-used-weight-loss
- U.S. Food and Drug Administration (FDA). (2025, August 15). FDA approves treatment for serious liver disease known as 'MASH'. Retrieved from https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-treatment-serious-liver-disease-known-mash
- Vidovszky, A. (2025, January 28). Do GLP-1 Supplements Work? diaTribe.org. https://diatribe.org/diet-and-nutrition/do-glp-1-supplements-work
- Wegovy [package insert]. Updated November 2024. Novo Nordisk. Accessed 02/19/2025 at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ee06186f-2aa3-4990-a760-757579d8f77b
- White, G. E., Shu, I., Rometo, D., Arnold, J., Korytkowski, M., & Luo, J. (2023). Real-world weight-loss effectiveness of glucagon-like peptide-1 agonists among patients with type 2 diabetes: A retrospective cohort study. Obesity (Silver Spring, Md.), 31(2), 537–544. https://doi.org/10.1002/oby.23622
- Yao, H., et. al. 2024. Comparative effectiveness of GLP-1 receptor agonists on glycaemic control, body weight, and lipid profile for type 2 diabetes: systematic review and network meta-analysis. In: The BMJ. DOI: https://doi.org/10.1136/bmj-2023-076410
- Zepbound [package insert]. Updated January 2025. Eli Lilly and Company. Accessed 02/19/2025 at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=487cd7e7-434c-4925-99fa-aa80b1cc776b
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